A communications system designed in the 1960s as part of preparation for surviving nuclear war evolved globally into what is now referred to as the "Internet". In effect, the Internet is a multitude of networks which interconnect to transfer information but without the supervision of an oversight organization. In 1989, a physicist at the European Particle Physics Laboratory known as CERN proposed a worldwide web (WWW), a set of protocols layered upon the Internet which utilize hypertext, a technique for presenting and relating information which uses links rather than linear sequences. The Web was demonstrated in 1991 and expanded rapidly with hypermedia and multimedia software. Developed in concert with the Web were a series of software interface programs structured to aid in navigating the Web which are called "browsers". In this regard, a team of programmers at the National Center for Supercomputing Applications (NCSA) developed a non-proprietary graphical interface browser for the Web which was released in 1993 under the name "Mosaic". Within six months of that release, more than two million people downloaded Mosaic from the NCSA host computer in Champaigne, Ill. The Mosaic browser is a cross-platform application, such that it is able to run in various different computing environments, i.e. PC-Windows, Macintosh, Amiga, and Unix-based systems. In the internet, for example, the Mosaic browser is deemed a "client"--an applications program running on a desktop computer and sending out requests for information typically to remotely located computer programs referred to as "servers". Within the Web, the client is responsible for displaying the information it receives from the server, and the server is responsible for performing the computation needed to retrieve the information the client is going to display, controlling access to that information, and recording usage statistics. The NCSA's Mosaic interface is a common one in use and when employed as an electronic publishing vehicle, its native HyperText Transfer Protocol (HTTP) (CERN, 1994a) is the protocol for communication with servers. Information itself is transmitted in HyperText Mark-up Language (HTML) which, in turn, is an application of the international (ISO, 1986) Standard Generalized Mark-up Language (SGML). Information transmitted in HTML is interpreted and displayed by the client as text and graphics on the user's screen or printer. See generally: Hickey, "Present and Future Capabilities of the Online Journal" LIBRARY TRENDS, vol. 43, No. 4, Spring, 1995, pp 528-543.
Several browsers are now available, for example Netscape Navigator has become widely used. More recently, a Web browser termed "Hot Java" has been developed by Sun Microsystems, Inc. using a language also developed by the Sun organization called "Java" which allow additional capabilities found desirable by database operators and developers seeking to serve internet clients. For example, code can be downloaded dynamically from the server to the user or client at the desktop level.
While the Web browsers have multi-platform capabilities, they have been constrained to use the text or character forming facilities of the individual platforms. Thus, there has been essentially no control available to the server for the final structuring of text and, particularly, the facilities from one platform to another are varied such that they do not have a commonality in techniques for painting characters upon a screen. This becomes a hindrance where scholarly text becomes the subject of Web distribution. For example, technical journals typically will incorporate glyphs or characters associated with mathematical equations and the like, for which platform-based character formations will have no counterparts. To overcome these difficulties, bit-map defined characters may be employed, preferably along with device independent typesetting specification files (DVI) which call for a particular character and font, and exactly define where the character should be positioned, for example, to the extent of 1/64,000th of a point (a point is 1/72nd of an inch). Such device independent files are described in U.S. Pat. No. 4,803,643, entitled "System and Method for Creating Memory-Retained, Formatted Pages of Text, Tabulation, and Graphic Data" by Hickey, issued Feb. 7, 1989. With such DVI systems, information can be transmitted to the client as to the proper position of the character at hand, its definition, and the like. However, because of the variety of facilities exhibited by various platforms to which the server transmits, the raster defined pixel matrixes by which characters are fashioned will vary and be unable to accommodate the precise DVI character positioning information. Typically, a given character is horizontally "relocated" to the closest available pixel on the screen or raster. In effect, a spatial character shift then becomes observable at a display with resultant text-character renditions which are disconcerting to the user. For example, characters of a given word may be bunched together or spread apart beyond their proper spacing definition. Particularly when viewed upon a dynamic screen or display, such spatial vagaries are quite disquieting. Generally, pixels in a display matrix are spaced apart between about 1/70th and 1/100th inch. While a displacement of that amount or only one half of that amount seems dismissable it will be very visible and distracting to the reader.
An approach in the field of computer graphics for improving image qualities, particularly with respect to "staircasing" or "jaggies" has been through resort to antialiasing which may employ any of a variety of sampling techniques to develop gray-scale variations in the definition of images. In effect, the human eye-neural system synthesizes the resultant gray-scale image and mentally interprets it as an improved sharper image. Such approaches to character display improvement were undertaken by investigators at about the time of the introduction of the personal computer. See, for example:
1. Negroponte, N., SoftFonts. Proceeding, Society for Information Display, 1980 PA1 2. Schmandt, C., Fuzzy Forms: Analog Models Inprove Digital Text Quality, Conference of Exhibition of the National Computer Graphics Association (4th, 1983) PA1 3. Schmandt, C. Soft Typography, Information Processing '80. Proceedings of IFIPS, pp.1027-1032 PA1 4. Wilkes, A. J. and Wiseman, N. E., A Soft-edged Character Set and Its Derivation, The Computer Journal, vol. 25, No. 1, pp 140-145 (1982) PA1 5. Schmandt, C., Greyscale Fonts Designedfrom Video Signal Analysis, Architecture Machine Group, Massachusetts Institute of Technology PA1 6. Gupta, S., Bantz, D., Sholtz, P., Evangelisti., C., and DeOrazio, W., YODA: An Advanced Display for Personal Computers, IBM J. Res. Develop., vol. 31, No. 1, pp 44-57 (Jan. 1987) PA1 7. Warnock, J. E., The Display of Characters Using Gray Level Sample Arrays, Comput. Graph. 14, No. 3, 302-307 (July 1980) PA1 8. Computer Graphics, Principles and Practice, 2d Ed., pp 976-979, Addison-Wesley Co., Inc. (1990) PA1 (a) determining from the typesetting specification file and the given pixel matrix resolution, the positional error with respect to the ideal location for each character of the text when located at the nearest pixel available at the display, PA1 (b) determining for a text character whether the error is greater than a predetermined portion of the pixel-to-pixel spacing, PA1 (c) accessing the image font file for the compressed character image template corresponding with the text character, PA1 (d) shifting the compressed character image template in a predetermined direction an amount representing at least one pixel when the determination (b) is that the error is greater than the predetermined portion of the spacing, PA1 (e) filtering and scaling the character image template to derive an anti-aliased display character at the select font size, PA1 (f) displaying the display character at the platform display, and PA1 (g) reiterating steps (a)-(f) for characters of the text. PA1 (a) determining from the typesetting specification file and the given pixel matrix resolution the positional error with respect to the ideal location for a character of the text when located at the nearest pixel available at the display, PA1 (b) determining for the character of the text whether the error is greater than a predetermined portion of the pixel-to-pixel spacing resolution, PA1 (c) when the error is determined to be greater than the predetermined portion of the pixel-to-pixel spacing resolution, then determining whether an anti-aliased display character has been generated in accordance with step (g) hereof and cached in temporary memory and, in the event that it has been cached, then going to step (i) hereof, PA1 (d) when the display character has not been cached, accessing the image font file for the compressed character image template corresponding with the character of the text, PA1 (e) decompressing the accessed compressed character image template to an extent identifying character image transitions from relative black and white runs of pixels, PA1 (f) when the error is determined to be greater than the predetermined portion of the pixel-to-pixel spacing, carrying out an effective shifting of a predetermined number of pixel positions in a predetermined horizontal direction at the decompressed character image template, to derive a shifted character image template, PA1 (g) then filtering and scaling the shifted character image template to produce an anti-alias display character of the select font size, PA1 (h) caching the anti-aliased display character in temporary memory, PA1 (i) displaying the display character at the platform display, and PA1 (j) reiterating steps (a)-(i) for characters of the text.
Anti-aliased image generation also is undertaken with varying hues or colors. See in this regard:
While the anti-aliasing approach to character generation has served the purpose of presenting relatively higher quality characters on limited resolution displays, the need to achieve a form of sub-pixel positioning on a practical basis has persisted. In effect, the high resolution typesetting specifications do not translate into integer values at low resolution. Thus, the noted character positioning aberrations. Investigators have addressed this anomaly by looking to an approach carrying out a sub-pixel shifting utilizing a gray scale filtering process. See in this regard:
Filter derived sub-pixel positions or locations, sometimes called "phases", however, pose the problem of requiring immense amounts of storage and computational constraints which have remained unsolved. As the Internet system expands, however, an increasing demand follows for the an improved accessing and display of scholarly works. A technique for the practical generation of such materials at lower level resolution displays has heretofore proved to be an elusive goal.